Method and apparatus for making sound-records.



T. A. EDlSON. METHOD AND APPARATUS FOB. MAKING SOUND REOORDS.

,APPLIOATIN FILED AUG.30, 1904.

Patented Sept.20, 1910 4 BHIETB--SHEBT 1.

Y T. A. EDISON., METHOD AND APPARATUS FOR MAKING SOUND RECORDS.APPLIUATION FILED AUG.80, 1904.

970,61 5. Patented sepa 20, 1910.

4 SHEETS-SHEET 2.

T. A. BDISDN. METHOD AND APPARATUS FOR MAKING SOUND BBooBDs.

APPLICATION FILED 130.110, 1904.

Patented Sept. 20,1910.

4 HEIGHTS-:SHEET 3.

@dem 4 SHEETS-SHEET 4.

Patented sept.2o,191o.

T. A. EDISON. METHOD AND APPARATUS POR MAKING SOUND RECORDS.

APPLICATION FILED AUG.30, 1904.

l practically exact graph or other sound Arecords, but also for theexperiments in PATENT OFFICE.

THOMAS A. EDISON, 0F LLEWELLYN PARK, ORANGE, NEW JERSEY.

METHOD AND APPARATUS FOR MAKING SOUND-RECORDS.

Specification of Letters Patent.

Patented Sept. 20, 1910.

Application filed August 30, 1904. Serial N o- 222,702.

To all whom 'it may concern.'

Be it known that I, Tiioiiiiis A. EDISON, a citizen of the UnitedStates, residing at Llewellyn Park, Orange, Essex county, New Jersey,have invented a certain new and I mproved Method and Apparatus forMakingr Sound-Records, of which the following,r is a description. x

My 'invention relates to an improved apparatus for making phonograph, orother talking machine records, and in y object is to secure a soundrecord which shall be of uality, and at the saine uch a record whensedirectly on the phonorcproducing machine, but it is preferablyemployed as a master from which copies are obtained by any approvedprocess of duplication, as for ex ample, by a molding operation.

he invention is practicable for use not only for the ,production ofphonograph production of socalled gramophone records, wherein the recordexists as a sinuous groove of substantially uniform depth.

In making a sound record of either' of the types referred to, there arecertain factors time very loud. cured,may be used which enter into theoperations and by rea-' son of which the sounds is affected trulyrepresentative of the original sounds. The most objectionable of thesedisturbing' influences which I have encountered in my phonographicrecording, is due to the inertia and momentum of the dia liragm and therecording devices, carrie by or connected with the same. As a result,when thedia lira m is subjected to vibrations of considlerableamplitude, the momentum of the parts causes the recording knife lo cutto a disproportionately great depth, and this aberration is manifestedin the succeeding vibrations. Consequently, I find that the quality ofthe recorded sounds is in inverse ratio to the loudness thereof so thatwhen the attempt is made to make a very deep record, or a record ofgreat amplitilde, thelouder notes are generally of poor quality, and`are out of proportion to the notes vor sounds 'of less amplitude.Another disturbing inHuence, which I have encountered in myexperimentswith the phonograph, and by which the quality of the records isaffected, is d uc to the fact that the quality of the recorded so thatthe record isnoe..

cordel' l, (see Fig.

horns heretofore used have been responsive to certain toiles, eitherfundamental or sccondary, within the range of ordinary music, and inconsequence, such toiles are greatly emphasized and become objectionablydistorted in the reproduction. Obviously, the tones which may thusbecome unduly amplified depend upon the lcneth of the horn used,- butsince it has been heretofore neeessary to employ horns of considerablelength,

say from 18 to 3G inches, in order that (he sounds may be properlycollected to make the record loud enough for practical purposes, thetones to which they may be rcsponsive, either fundamental or secondary,will always exist in the range of ordinary music. .l am not aware thatthese objec tions have ever been successfully overcome, and heretofore,the volume of: a phonograph, or other sound record has been largelyrestricted. because of th'e same.

The object of my invention is to overcome these objections. i

To this end, the invention consists, in the features hereinafter setforth and claimed.

In order that the invention may be better understood, attention isdirected to the accompanying drawings,- forining a part .of thisspecification, and in which Figure ll is a diagrammatic view showinglaportion of the original master, or metallic Fig. 3 i, diagrammaticview of the amplified duplicate record. Fig. 4 a cross sectional viewthrough the recmdcr used in cutting the amplified duplicate,illustrating the same cutting to its full depth the scale being cnc-halfthat of Fig. 3. Fig. 5 a plan view of a preferred cmbodiirient of themechanical duplicating apparatus. Fig. 6 a cross sectional view showingthe shaving knife for trimmingF the blank to thc exact shape and size asthe original record. Fig. 7 a corrcspondinc' view showing the mechanismfor securing the amplified copy of the original record, and Fig. 8 asectional view on the line 8--8 of Fig. 6. In all of the above views,correspondinfr parts are rel'ircsented by the same numerals ofreference.

' ln carr Ying the method into elfect, l first make an original recordby means of a re- 2) of small cross section,

the record being of lon7 amplitude. Thus,

in Fig. l, l illustrate such a record, wherein themaximum width ot' therecord groove is only about one-half the available surface, or about onet\\u'iliuiiilie ltl; of' an inch. in making' such a record, l am enabledlov ein ploy a very short horn, say from tour to live inches in length,owing to the loiv amplitude-of the sounds to be recorded; and such a,horn is not responsive to an injin rions extent te any tones within therange of ordinary music, so that the objectionable funnel tones l maybeeliminated. l. find that records of this kind, although very faint, areof superior quality, not only beeause'the work imposed on the recorderis slight', and consequently, the recorder` is free to` more readilyrespond to the origina-l sounds, but also and principally, because thevibrations are not allected to a noticeable extent by the momentum ofthe parts, so that disturbances from that cause are praeticallyeliminated. Obviously, the quality of the master record so obtained willbe furn ther improved by the employment of a very A`short horn,explained, and by which the it is necessary that the surface on whichthe record is transferred should be et the exact shape as the metallicmaster.

It would be very difficult to secure ame tallie master tliat'would beabsolutely ey- :lindrical and much more dilllcult to secure a blank ofabsolutely the same size, and for this reason l prefer to malte use of'a shaving device, working in advance of the re coi-der and by means ofwhich the blank will be cut to the exact size and shape of the masterimmediately before the record is cut therein. A suitable apparatus forthe purpose is indicated in the drawings wherein the metal master 2 iscarried on the inandrel 3, and the blank l is carried on the mandrelThese mandrels are rotated simultaneously by any suitable gearing` at alow speed, so that the surface speed of the master is sullleiently lowas te prevent any l disturbing' mlluenee due to momentum or inertia otthe movingl parte. il carriage S is mounted to travel on rod l, and its'forward end is supported a regulating; screw S, lworking on a 'trentbar 9, l

will cut the blank to since in actual ora would be located very closetogether and a short lever would be used. Preferably,

the lever 1Q is in 'the 'form of a small truss,

to possess the maximum rigidity, and order to prevent any Hennig of thelever ope ation, l pieter to maintain it under itl a condition ofstress, as tor example," by

means of small adjustable tierods .13.

stressing the lever practically to the endv of the elastic limits, lsecure a perfectly rigid construction by means of Whichthe roest minutemovements of one end will be trans- Imitted to the tall extent attheotlier, end

thereof. At one end, the lever carries a shoe 14, made preterably ofsapphire,and adjustsey ed by a screwl` 15, said shoe bearing upon thesurface of the master 2 and being Wide enough to overlap several of therecord grooves thereon., This shoeniaybe carried from a spring 16, asshown. .fit its other end, the lever 12 carries a euttinUr or shavingknife 1,7,iiiade of sapphire, and of any suitf able shape for engagingthe blank 4t. Ji. spring 1S maintains the shoe le and knife 17 inengagement with the master and blank respectively.' Obviously, when themaster and blank are rotated, witlithe shoe le in engagement with theformer, the knife 17 the exact shape and size as the master. Thecarriage 6 also carries a duplicating lever 19, (see Fig. 7) whose pivotis so arranged asto give the desired ampliication. Ordinarily, ananiplilcation of two to one will be suli'eient.`

'lhis lever is constructed. like the lever l2, and is also maintainedunder normal ten limits, so to be tree from vibrations. At

vone end, the lever 1S* carries the reproducing ball 2O from thefn'ljustine,4 screw 21, and et the other end is provided with recorder22, which as shown in Fig. l, is 'preferably of a. diameter of about.040 of an inch.

The recorder and reprodueer are maintained in engagement with the blankand master respectively, by an adjustable spring 23.

ln order that there may .not be any lost motion at the pivots of thelevers 1:2 and 19, l preferably mount these levers on very small torsionWires 24 and V25, carried on the brackets 26 upon the carriage 6 andheld from rotary movementI by the screws 27. Consequently, any movementsof the levers 12 and, 19 are afforded by torsional elasticity et' thepivots 24e and 25, which movements are obvioasly slight, since themovements of the ends el? the levers rarely exceed a thousardh oi anineli, Iin practice. The reand 'averli closely adire shown, so that asound record will be cut in the blank 4 immediately after itl is trimmedoff to the proper shape. By means of the duplicating mechanismdescribed, the blank 4 will be provided with a record therein (see Fig.3) Whichivill correspond with that on` the original master, except thatit will be very much amplified. Such a record will be obviously ofsuperior quality since, of course, the mandrels 3 and 5 will be rotatedslowly enough as t0 prevent any momentum of the parts from affecting theduplication. The finished amplified duplicate record may now be useddirectl Vfor reproduction, but it is preferably emp oyed as a masterfrom which duplicates are 'secured in any suitable way,

such as by a molding process. Any other duplicati, process well known tothose skilled in t e art, may however, be employed for securing copiesfromsuch a master.

Having now described in invention, what I Claim as new therein an desireto secure by Letters Patent is as follows:

1. The process of making sound records, which consists. in mounting ablank'upon a. rotating support, trimming the blank and then, without anyalteration Iof the position of the blank upon its support, engaging withy the blank a recording st lus which 1s mechanically connected with areproducer stylus'trackinga master record, and rotat- 4ing' the 4masterand y.blank at such slow speed l as topracticallyf: .eliminate defectsdue to momentum and inertia of the moving parts. 2. The process ofmaking sound records, which consists 1n making a master record ofv lowamplitude, in rotating the same adjacent to a rotating blank, engagingwith the master and blank respectively a reproducer stylus and recordingstylus connected by an amplifying lever connection, and in rotating themaster and blank at such slow speed as to practically eliminate defectsdue to momentum and inertia of the moving parts, substantially as setforth.

3. The process of making sound records, which consists in first securinga record of low amplitude, in rotating the same adjacent to a rotatingblank, engaging a cutting knife with the blank, regulating the cuttingknife yby the rotating master whereby the blank will be trimmed to theexact shape of the master, and in mechanically recording on the blank anamplified copy of the record on the master by mechanical transference,substantially as set forth.

4. The process of making sound records, which consists in first securinga record'of low amplitude, in rotating the same adjacent to a rotatingblank, engaging a cutting knife with the blank, regulating the cuttingknife by the rotating master, whereby the blank will be trimmed to theexact shape of the master, and in mechanically recording on the blankimmediatelv after the action of the cutting knife an amplified copy ofthe record on the master-by meclian` ical transference, substantially asset forth.

5. The process of making sound records,

chanical transferencea duplicate of normal or desired amplitude,substantially as set forth. f

7. Apparatus for making sound records, which consists of tWo rotatinmandrels, one carrying a master and the ot ier a blank, of a pivotedlever, a shaving tool' carried by the level' and engaging the'blank, anda shoe on the lever engaging the master, as and for the purposes setforth.

8. Apparatus for making sound records, which consists of two'rotatinmandrels, one carryin a master and the ot er a blank, of a pivote lever,a shavin tool carried by the lever and engaging the b ank, and ashoe onthe lever engaging the master, a second lever, a recorder carried-bys'aid lever engaging the blank, and a reproducer carried y the sameengaging the recordon the inaster, as and for the purposes set forth.

9. In apparatus for making sound records, the combination with tworotating mandrels, one carrying a master record, and the other a blank,of a duplicating lever maintained under normal stress, a recordercarried by the lever and en aginnr ducer carrier? by tlie lever engagingthe record on the master, as and for the purposes set forth.

10. In apparatus for making sound records, the combination with tworot-ating mandrels,one carrying a master and the other a blank, of'aivoted lever, a shaving tool carried by the ever and engaging the blank,a shoe on the lever engaging the master and means for adjusting saidslice, as and for the purposes set forth.'

11. In apparatus for making phonograph records, the combination with tworotating mandrels, one carrying a master and the other-a blank, of apivoted lever maintained under normal stress, a shaving. tool carried bythe lever and engaging the blank, anda shoe on the lever engaging-themaster, as

and for the purposes set forth.

l2. In'apparatus for making sound records, the combination with tworotating the blank, and a repro-` mandrels, one carrying a master andthe other a blank, of a pivoted lever, tie rods for nmnvnning the loverUnder Dorn'xzzl sirva-, a

Shaving ool carried :at ono'ond of the lover und ongugmg' the blank, andn shoe. 1t ixo other end of tho lever engaging the. musing' mandi-els,one Carrying a master and tho other :a blank, of u lever mounod on nfixed pivot capable of torsional movomoni, a. shzwing tool carried atono end of the lover and engaging :L blank, and n, shoe cnrrod at ihooilwr om! ofthe'lover engngngg the musor, n." :lud for the plilrpososSoi; forth.

14. h1 apparatus :for milking sound rw ords, ho combination with tworo'atng n'mndror, one carrying fho muster record and hf: other :l blank,o1: a duplcang lover moumlod ou a torsional pvot, and a reproduccrcarried. by ih@ lover and engaging the record or. the muster, s and forthe purposes phonograph@ transfer duplicating mech; u n, a transferlever consisting of a truss nmntuinod normaly under srress with in tilimit of elasticity, :1s set forth. A

This specification signed and witnessed zhs frd day of Aug. 1904.

THOM S A. E )l SON.

W i messes "INA C. AGRTHUR.

